File cabinet combination lock



y 1959 J. G. SHMORHUN' 2,884,778

FILE CABINET COMBINATION LOCK Filed Aug. 50, 1954 4 Sheets-Sheet 1 JOHN G. SHMORHUN ATTORNEYS May 5, 1959- JKGT-SHMORHUN FILE CAB INET'CQMBINATION LOCK I Filed Aug 30', 1954 4 Sha ets-Sheet 2- y 1959 J. GTSLHMORIHUN 7 2,884,778

FILE CABINET COMBINATION LOCK Filed' Aug. 30, 1954 4 Sheets-Sheet 3- y 1959 .1. G. SHMORHUN 2,884,778

FILE CABINET COMBINATION LOCK Filed Aug. 30, 1954 I 4 Sheets-Sheet .4

Ill]! 5 mum VII'IIIIIIII INVENTOR JOHN G. SHMORHUN FILE CABINET COMBINATION LOCK John G. Shmorhun, Rochester, N.Y., assignor to Sargent & Greenleaf, Inc., Rochester, N.Y., a corporation of New York Application August 30, 1954, Serial No. 453,070

8 Claims. (Cl. 70-303) The present invention relates in general to combination locks, and more particularly to combination locks of the type having means for preventing the combination of the lock from being detected by unauthorized persons which is especially adapted for use with conventional file cabinets and the like.

Locks of the type commonly referred to as combination locks are dependent generally for their operation upon the alignment of a plurality of rotatable disks, commonly called tumblers, to permit operation of a bolt. Locks are commonly provided with three of such tumblers, each having a peripheral recess or gate to be aligned to permit retraction of the bolt. The security of such locks is dependent upon the fact that the numbers of orders or permutations of the possible relative positions of the tumbler gates before the gates are brought into registry is so large that the chance of these gates being aligned by a person not familiar with the combination is negligibly small.

The tumblers are rotated upon a fixed sleeve or shaft on which they are loosely journalled by means of a driving cam which is directly connected to the operating knob or dial. The driving cam is provided with a peripheral gate adapted to receive a nose on the end of a pivoted fence lever having an integral fence which normally extends transversely across the edges of all the tumblers. Conventionally, the fence is held in a position slightly spaced from the outer peripheries of all the tumblers with the axis of the fence parallel to the axis of the sleeve on which the tumblers are journalled. However, because of difficulties in manfacturing, it is practically impossible to manufacture the parts of locks to such close tolerances that the same slight differences in spacing will occur between the peripheries of the tumblers and the fence. By very careful manipulation of the driving cam to position the tumblers so that the fence drops first against the edge of the highest tumbler, and then the progressively lower tumblers, a skilled person can detect by touch or by very minute sound the alignment of the gates with the fence and thereby break the combination. This manipulation of the driving cam to drop the fence against the tumbler peripheries has been possible because of the peripheral gate in the driving cam which is designed, when aligned to receive the nose of the fence lever, to permit the fence lever under force of gravity or resilient bias to shift in a direction tending to seat the nose in the driving cam gate, which movement of the fence lever shifts the fence mounted thereon toward the tumbler peripheries.

Means have heretofore been provided in such combination locks for preventing the fence lever nose from entering to any extent into the driving cam gate, and in some cases for preventing the fence lever from contacting the driving cam, during the period when the tumblers are being rotated. These means have in some cases included a provision for preventing further movement of the tumblers when the driving cam is conditioned to per mit its peripheral gate to receive the nose of the fence lever, so as to prevent any manipulation of the tumblers during the period when the fence may be shifted into physical contact with the tumbler peripheries. An example of such means is disclosed in United States Patent No. 2,575,674, issued to Harry C. Miller on November-20, 1951.

It has been found desirable to incorporate such additional security provisions in combination locks of the type which are particularly adapted for use in file cabinets and the like, wherein the lock should be fixed in the limited space available between the reciprocable drawers or trays and the outer side walls of the file cabinet. Locks heretofore available for use in file cabinets and the like where only a portion of the dial need be exposed to view, have employed primarily exposed, edge indexed tumblers which must be individually manually adjusted to align preselected portions of the several tumblers to permit retraction of the bolt. The direct adjustment of the individual tumblers makes it a relatively simple matter for unauthorized persons to detect the combination of the lock through careful manipulation of the tumblers when the bolt and fence are placed under stress.

An object of the present invention is the provision of a combination lock of the type in which means are provided for preventing manipulation of the dial in a manner to give an indication of the position of the tumbler gates to unauthorized persons, which is particularly adapted for use in file cabinets and the like.

Another object of the present invention is the provision in a combination lock of a novel construction for accommodating the lock to the relatively limited space available in conventional file cabinets.

Another object of the present invention is the provision in a combination lock of the type adapted to be accommodated in the limited spaces available in file cabinets of a novel association between the bolt mechanism of the lock and a plunger mechanism associated therewith for controlling interlock linkages of a filing cabinet whereby the plunger may be retained in unlocked position following unlocking of the lock and manually return to locked position without further adjustment of the lock mechanism.

Another object of the present invention is the provision in a combination lock of the type having means for pre venting operative engagement of the fence lever and driving cam during adjustment of the tumblers and means for manually conditioning the driving cam gate to receive a portion of the fence lever, of means for locking the dial against rotation during manipulation of the driving cam conditioning means.

Another object of the present invention is the provision of a novel combination lock especially adapted for file cabinets having means for holding the fence lever out of operative engagement with the driving cam gate during adjustment of the tumblers and means rotatable relative to the dial for conditioning the driving cam gate to receive a portion of the fence lever, wherein an arrangement is provided for preventing rotation of the dial during rotation of the driving cam gate conditioning means relative thereto.

Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, illustrating only preferred embodiments of the invention.

In the drawings:

Figure l is a perspective view illustrating a combination lock constructed in accordance with the present invention positioned in a conventional file cabinet.

Figure 2 is a bottom plan view of a combination lock embodying the present invention, with portions of the lock housing cover plate removed to expose portions of the internal construction of the lock to view.

Figure 3 is a vertical longitudinal section view of the combination lock, taken along the lines 33 of Figure 2.

Figure 4 is a vertical transverse section view of the lock, taken along the lines 4-4 of Figure 3.

' Figure 5 is a bottom plan view of a combination lock with portions of the bottom cover plate removed, illustrating components of the lock in unlocked condition.

Figure 6 is a vertical transverse section view of the lock, taken along the lines 66 of Figure 3.

Figure 7 is a horizontal section view of the lock taken along the lines 7--7 of Figure 6, illustrating the arrangement of the interlock pin guide groove in the lower surface of the driving cam conditioning disk.

Figure 8 is a fragmentary perspective view with parts of the dial and driving cam conditioning disk broken away to illustrate the dial interlocking mechanism.

Figure 9 is a top plan view of the bottom cover plate.

Figure 10 is a vertical transverse section view of a combination lock for file cabinets having a modified form of dial interlock mechanism.

Figure 11 is a horizontal perspective V16W taken along the lines 1111 of Figure 10; and

Figure 12 is a fragmentary perspective view of the dial and driving cam conditioning disk with parts broken away illustrating the construction of the modified form of dial interlock mechanism.

The combination lock herein disclosed embodies improvements in file cabinet combination locks of the type disclosed in the copending patent application of Harry C. Miller, bearing Serial Number 274,904, filed March 5, 1952, now Patent No. 2,687,639, dated August 31, 1954. Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures thereof, the combination lock embodying the present invention, indicated generally by the reference character 1% is especially designed and adapted to be disposed in the portion of a conventional file cabinet, generally indicated by-the reference character 11 lying immediately rearwardly of the top framing strip 12 in a position to overlie the upper edge of the movable file cabinet drawer 13 in general alignment with the center of the top framing strip 12. The lock is formed in a compact arrangement whereby it will lie wholly within the space defined between the top surface of the file cabinet 11 and the upper edge of the drawer 13. The lock 10 is designed to control and cooperate with a conventional file cabinet linkage system 14 for restraining the drawer 13 from being withdrawn from the file cabinet.

To this end, the lock 10 is formed of a lock housing body 15 adapted to be secured by suitable screws or other conventional fastening means to the top framing strip 12 of the file cabinet. A bottom cover plate 16 is substantially coextensive with the rectangular plan outline of the lock housing body 15 to be fitted onto and secured to the lower face of the lock housing 15. Intermediate the lateral edges of the lock housing 15 is an integral upwardly projecting cylindrical tumbler housing portion 17 terminating at its uppermost end in the upper disk-like wall 18 forming, in the housing body 15, in cooperation with the cylindrical side walls a downwardly opening cylindrical tumbler chamber 19 which is closed at its lower end by the bottom cover plate 16. In the preferred embodiments illustrated in the drawings, there is shown a special construction designed to render the lock highly resistant to attempts to break the combination by drilling through the file cabinet walls and selected portions of the lock. To this end, the upwardly facing surface of the disk-like top wall 18 is recessed to accommodate a circular plate 2%) formed with a downwardly projecting peripheral flange, the plate 21 being highly resistant to attempts to drill into the tumbler chamber 19 from above the lock.

The cylindrical tumbler housing portion 17 is provided with an integral hollow tubular boss 21 coaxially arranged in relation to the medial axis of the cylindrical housing 17 and projecting downwardly through substantially the length of the tumbler chamber 19. The integral boss 21 supports a plurality of tumblers 22, 23 and 24 loosely journalled in side-by-side relation and having washers and rotatable flyers associated with each tumbler and arranged by the successive pairs of tumblers in accordance with conventional lock construction practice to provide lost-motion connections between each tumbler and its next uppermost tumbler. The assembly of tumblers, washers and flyers is freely rotatable on the boss 21rbut are held against longitudinal movement thereon by means of a suitable annular collar 25 accommodated in a complementary annular groove adjacent the lower end of the boss 21.

An externally threaded hollow sleeve 26 is disposed within the bore of the boss 21. Threaded on the lower end of the sleeve 26 and keyed thereto against relative rotation is a driving cam 27. The driving cam 27 is especially constructed so as to resist manipulation of the lock in a manner which will disclose the combination thereof to unauthorized persons, and to this end is provided with a disk-like body having a peripheral recess or gate 28. Carried upon the face of the disk-like body portion of the driving cam 27 disposed away from the tumblers between a pair of guide blocks 29 having facing guide grooves 30 formed in the adjacent surfaces thereof is a slide 31 corresponding in length to the maximum diameter of the driving cam 27 and having opposite ends 32 and 33 arcuately curve to form continuations of the circular periphery of the driving cam 27. As will be observed from an inspection of Figure 2, the slide 31 when positioned with the arcuately curved ends 32 and 33 thereof in alignment with the periphery of the driving cam 27 effectively shields the driving cam gate 23 from being entered by a body bearing upon the periphery of the driving cam.

The slide 31 is designed to be reciprocated diametrically of the driving cam 27, by means to be later described, so as to expose the driving cam gate 28 beyond the arcuate surface 32 of the slide 31, and the periphery of the driving cam is recessed as indicated at 34 to accommodate a driving pin 35 projecting toward the tumblers from the slide 31 to engage the flyer associated with the lowermost tumbler 22 upon rotation of the driving cam and selectively transmit movement of the driving cam to the tumbler 22. When the slide 31 is shifted diametrically of the driving cam 27 so as to position the arcuate end 32 thereof below the bottom of the driving cam gate 28, the driving pin 35 is projected radially beyond the outer edge of the flyer associated with the tumbler 22 so as to eifectively break the driving connection between the driving cam and tumblers.

The upper surface. of the lock housing body 15 is recessed, as indicated. at 36, in a circular path having a radius greater than that of the cylindrical tumbler housing 17 and to a depth providing an annular recess 37 surrounding the. outer cylindrical walls of the tumbler housing portion 17. Into the. recess 36 in surrounding relation with the portion, of the cylindrical tumbler housing 17 projecting therein is a cylindrical dial 38 of substantial thickness. The dial 38 is formed of an upper disk portion 39 overlying the top wall 18 of the cylindrical tumbler housing 17 together with a peripheral downwardly projecting flange 40 integral with the top disk portion 39 and constituting a bevel section 41 flaring outwardly from the periphery of the disk portion 39 and a terminal flange portion 42 projecting at right angles to the disk portion 39 having a knurled exterior surface to facilitate manual. rotation of the. dial 38. The bevelled portion 41 is provided with index markings and numbers on the outer surface thereof. corresponding to the arrangement of markings on conventional combination lock dials. The disk portion 39 of the dial 38 is press-fitted or otherwise suitably secured, as by threading or keying the same to the upper end of the externally threaded hollow sleeve 26 projecting through the integral bos's21, whereby rotation of the dial 38 is transmitted to the driving cam 27.

The lower face of the top disk portion .39 of the dial 38 is cylindrically recessed to define shoulders 43 adapted to intimately fit over the uppermost portion of the cy1in drical tumbler housing 17 so that the tumbler housing 17 serves as a bearing about which the dial 38 is rotated.

Positioned above and incoaxial relation with the dial 38 is a, slide control disk 45 of substantially the same diameter as the top disk portion 39 of the :dial 38. The

slide control disk 45 is provided with a lower face 46,

which is complementary to and positioned to rest upon the upper face of the dial 38, thedisk 45 terminating in a downwardly projecting peripheral flange 47 which envelopsthe upper edge of the dial 38, the flange 47 having aknurled outer surface to facilitate manual rotation of the disk 45 from the edge thereof. vThe slide control disk 45 is also provided with anuaperture 49 at the center thereof which is seated in relative non-rotational relation with a slide control spindle 50 which extends coaxially through the hollow bore of the sleeve 26.

A slide cam 51 is fixed to the lower end of the spindle 50 and is positioned within the irregular opening 52 in the slide 31 to engage the lower and upper irregular surfaces 53 and 54 respectively, bounding the slide opening 52 for lowering the slide 31 to the position illustrated in Figure 5 upon 180 degrees rotation of the slide control disk 45 in one direction and to raise the slide 31 into the driving cam gate-closing position illustrated in Figure 2 upon a like rotation of the slide control disk 45 in the opposite direction. v I

A fixed arbor 55 disposed parallel to the axes of the tumblers 2224 and spaced from the peripheries thereof isprovided in the tumbler chamber 19 for supporting a fence lever 56. The fence lever 56 is provided with a fence 57 which is fixed relative to the fence lever 56 and which extends along a transverse axis of the peripheries of each of the tumblers 22, 23 and 24 to be shifted into and out of the peripheral gates 22', 23, 24 of the tumblers when the same are aligned with the fence 57 and the fence lever 56 is rotated in a clockwise direction from the position shown in Figure 2. The fence lever 56 is of general bell crank shape which is resiliently biased by a spring 56 to rotate in such clockwise direction, and is provided with a nose 58 to be received in the driving cam gate 28 when the same is aligned therewith, and a projection 59 which is angularly related to the axis of the nose 58 for controlling retracting movement of a rectilinearly slidable bolt 60, the bolt having a recess 61 for receiving the fence lever projection 59.

The bolt 60 is slidably supported in a complementary groove in the lock housing body 15 extending longitudinally of the housing with the inner end of the bolt 60 having the recess 61 projecting slightly into the tumbler chamber 19. A T-shaped slot 62 is provided in the medial portion of the bolt 60 to receive a T-shaped stud 63 projecting into the bolt-receiving groove from the locking housing body 15, the T-shaped stud 63 being shorter than the slot 62 and a compression coil spring 64 being provided in the slot 62 between one end thereof and the adjacent end of the T-shaped stud 63 to resiliently bias the bolt 60 away from the tumbler chamber 19.

The outer end of the bolt 60 is adapted to control a plunger 65 movable along an axis perpendicular to the axis of movement of the bolt 60, the inner end of the plunger 65 being coupled to the cabinet locking linkage system 14. To this end, the plunger 65 is formed of an elongated body of substantially rectangular cross section seated within a chamber 66 of complementary cross section provided in the housing 15. The rearwardly disposed portion of the plunger 65 within the chamber 66 is provided with a depending stop shoulder 67 facing toward the front of the file cabinet to be engaged by the portion of the bolt 60 projecting into the chamber 66 when the plunger 65 is shifted to its rearward limit of movement and hold the plunger 65 against return toward the front of the file cabinet. Limit shoulders 68 and 69 are provided on the plunger 65 to engage the rear walls of the chamber 66 and limit inward movement of the plunger, and an upwardly opening recess 70 is formed in the plunger to receive a coil spring 71 compressed between the rear wall of the chamber 66 and the front wall of the plunger recess 71 to resiliently urge the plunger toward the front of the file cabinet. A cylindrical finger button 72 formed integral with the plunger 65 projects forwardly thereof through a complementary aperture in the front wall of the lock housing 15 and the top framing strip 12 of the file cabinet, and a recess 73 opening toward the tumbler chamber 19 is formed in the plunger 65 intermediate the ends thereof to receive a hardened drillproof plate 74 fitted into a complementary slot in the lock housing 15 and projecting into the plunger chamber 66 to prevent the introduction of shim stock into the plunger chamber 66 to a sufiicient degree to effect actuation of the bolt. A rectangular cross section rear end portion 75 of the plunger 65 projects through the rear wall of the lock housing 15 to which any suitable file cabinet linkage system 14 may be coupled to be controlled by rectilinear movement of the plunger.

The bottom cover plate 16, as is illustrated in detail in Figure 9, is adapted to close the lower end of the downwardly opening tumbler chamber 19 in the lock housing 15 and is provided with a pair of upwardly projecting arcuate stop members 76 having inwardly facing cylindrical segment surfaces 77 of a slightly greater radius than the-radius of the driving cam 27 terminating in stop shoulders 78. The stop shoulders 78 are spaced a greater distance apart than the width of the slide 31 to permit radial shifting of the slide 31 relative to the driving cam 27 to project the end 33 thereof beyond the circumference of the driving cam and a limited amount of rotation of the driving cam and projected slide. The stop shoulders 78 adjacent the sides of the projected end 33 of the slide 31 in such position prevent rotation of the driving cam and tumblers, while the arcuate faces 77 prevent radial shifting of the slide 31 out of alignment with the circumference of the driving cam 27 at all other orientations of the driving cam. A groove 79 is also provided in the upper face of the bottom cover plate 16 to accommodate the lower edge of the hardened drill-proof plate 74.

Assuming the lock to be in locked condition as illustrated in Figure 2, the lock is unlocked by rotating the dial 38 in counterclockwise direction for three full revolutions to bring a preselected dial marking in alignment with a fixed index mark, then for two revolutions in the opposite direction to align another dial marking with the index mark, and then another full revolution in a counterclockwise direction to align the third dial marking with the index mark. The slide control disk 45 rotates with the dial 38 during these manipulations due to the spring biased ball and socket formation 80 resiliently connecting these components. The rotation of the dial 38 transmitted through the sleeve 26 to the driving cam 27 imparts the desired rotation to the tumblers through the driving pin 35 carried by the slide on the driving cam 27 and the flyers forming the lost-motion connection between the tumblers. This manipulation of the dial 38 in accordance with the combination of the lock is for the purpose of aligning the tumbler gates 22', 23' and 24' with the fence 57 to receive the fence upon counterclockwise rotation of the fence lever 56.

To effect rotation of the fence lever 56, the dial 38 must then be returned in a clockwise direction in the preferred embodiment to align the zero marking on the dial with the fixed index mark of the look so that the end 33 of the slide will be positioned to be received between the stop shoulders 78 on the stop members 76. The slide control disk 45 must then be rotated for approximately 180 degrees relative to the dial 38 while the dial 38 remains fixed to effect retraction of the slide. This rotation of the slide control disk 45, transmitted through the spindle 50 to the slide cam 51, brings the radially projecting portion of the slide cam 51 against the surface 53 of the slide aperture 52 to project the end 33 of the slide beyond the circumference of the driving cam 27 and position the end 32 of the slide below the bottom of the driving cam gate 28. This movement of the slide 31 to expose the driving cam gate 28 permits the nose 58 of the fence lever 56 to be shifted into seating engagement in the driving cam gate 28 under the influence of the spring 56. Limited rotation of the driving cam 27 with the slide 31 projected is permitted between the stop shoulders 78, so that the driving cam 27 may be rotated to a sufiicient degree with the fence lever nose 58 seated in the driving cam gate 28 to pivot the fence 56 and retract the end of the bolt 60 from the plunger chamber 66. This frees the stop shoulder 67 of the plunger from contact with the bolt 60 to permit the plunger 65 to be shifted toward the front of the lock and file cabinet by the coil spring 71. This forward movement of the plunger 65 effects suflicient movement of the file cabinet linkage system 14 to unlock the drawers of the file cabinet. Engagement of the depending projection 72' on the forward portion of the plunger 65 with the front wall of the plunger chamber 66 establishes the forward limit of movement of the plunger 65. An inspection of Figure will reveal that when the plunger 65 is in its forwardmost position the depending portion of the plunger between the stop shoulder 67 and limit shoulder 69 is in alignment with the end of the bolt 60 so that return of the bolt into the plunger chamber 66 under the action of its spring 64 is prevented. Accordingly, to relock the lock, it is necessary to manually shift the plunger 65 inwardly of the lock until the bolt 60 snaps back into locking relation with the plunger after which the slide control disk 45 may be returned to its original position to retract the slide 31 to its normal aligned relation with the driving cam 27 and the dial 38 manipulated to shift the tumblers out of alignment.

An interlock arrangement is provided in the file cabinet lock to prevent movement of the dial 38 and therefore of the driving cam and tumblers during actuation of the slide control disk 45 to project the slide and expose the driving cam gate. In this way, all rotary motion of the tumblers during the period when the fence may be brought into light contact with the tumblers is prevented to thwart attempts of unauthorized persons to detect the combination of the lock. This interlock mechanism comprises, in the embodiment illustrated in Figures 6, 7 and 8, a pivoted interlock pin 81 which is disposed in substantially parallel relation with the axis of the tumblers 2224 and is mounted on a supporting block 82 having a vertically extending groove 83 in which the interlock pin 81 is seated and a pivot pin 84 by which the lower end of the pin 81 is pivoted to the block 82. The block 82 is formed of a transverse cross section complementary to the spacing between the flange 40 of the dial 38 and the Vertical wall of the cylindrical tumbler housing 17 and is fixed to the dial 38 as by screws or other convenient securing means. The upper portion 85 is preferably cylindrical in cross section and projects through a radially extending slot 86 in the top portion of the dial 38, the slot 86 permitting limited pivotal movement of the interlock pin 81 in the plane of the radius of the dial 38. The downwardly disposed face of the slide control disk 45 is provided with a guide groove 87 in which the upper cylindrical portion 85 of the interlock pin 81 is seated when the disk 45 is positioned in overlying relation with the dial 38. A notch 88 is formed in the exterior surface of the side wall of the cylindrical tumbler housing 17 to receive a portion of the interlock pin 81 when the same is shifted about its pivot pin 84 toward the medial axis of the tumblers and tumbler housing 17, and the dial 38 is in a preselected position of orientation relative to the housing 17, preferably with the zero marking of the dial aligned with the fixed index mark. The guide groove 87, as illustrated in Figure 7, follows a path from points of greatest radius at the extremities thereof, at which the interlock pin 81 will be disposed vertically out of operative engagement with the tumbler housing notch 88 to a point of smallest radius at the mid-point of the groove and progressively diminishes in radius from the extremities of the groove. By this expedient, immediately when the operator commences rotation of the slide control disk 45 after the combination has been set up by the dial 38, the upper cylindrical end of the interlock pin 81 seated in the guide groove 87 will be shifted inwardly toward the center of the tumbler housing 17, bringing the intermediate portions of the interlock pin 81 into the notch 88 in the cylindrical housing 17 to interlock the dial 38 with the cylindrical housing 17 and prevent rotation of the dial 38 until the slide control disk 45 is rotated to a sufficient extent to shift the interlock pin 81 through the entire length of the groove 87. This same extent of rotation of the slide control disk 45 effects full projection of the slide 31 from the position illustrated in Figure 2 to the position illustrated in Figure 5. Return of the slide control disk 45 to its original position shifts the interlock pin 81 again through the entire length of the guide groove 87 to return the interlock pin 81 when the pin is seated at the upper end of the groove 87, as viewed in Figure 7, at which point the interlock pin 81 will again be removed from the tumbler housing notch 88 to free the dial 38 for rotation relative to the tumbler housing 17.

A modified version of this interlock mechanism is illustrated in Figures 10 to 12, inclusive, of the drawing. In this version, the interlock pin, indicated by the reference character 90, is in L-shaped form having a horizontal portion 91 and a vertically depending portion 92. The horizontal portion 91 is disposed in a radially extending groove 93 in the top portion of the dial 38 and the depending tail portion 92 of the interlock pin projects through a slot 94 at the outer extremity of the groove 93 which opens toward the upper portion of the lateral face of the side wall of tumbler housing 17. The radial groove 93 in the dial 38 is somewhat longer than the horizontal portion 91 of the interlock pin 90 to permit radial movement of the interlock pin from an outermost position wherein the inwardly facing edge of the depending tail portion 92 is positioned outwardly of the side wall of the tumbler housing 17 to a position seating the tail portion 92 of the interlock pin 90 in a complementary notch 95 formed at one radial position in the side wall of the tumbler housing 17. An upwardly projecting stud 96 is formed on the horizontal portion 91 of the interlock pin 90 to be received in a guide groove 97 formed in the downwardly facing surface of the slide control disk 45. The guide groove 97 follows the path illustrated in Figure 11 and the stud 96 of the interlock pin 98 is normally seated at one end of the groove 97. The ends of the groove 97 are a greater distance from the center of the disk 45 than the other portions of the groove and position the interlock pin at the outermost position within the slot 93, with the inner edge of the depending tail portion 92 disposed outwardly of the adjacent lateral peripheral surface of the tumbler housing 17. Upon rotation of the slide control disk 45 relative to the dial 38 from. this position to project the slide 31 on the driving cam 27, the interlock pin 98 is shifted radially toward the center of the tumbler housing 17 by the gradually diminishing radius of the guide groove 97 relative to the axis of the disk 45 to seat the depending tail portion 92 of the interlock pin 90 in the peripheral notch 95 and interlock the dial answer 38 against rotation relative to the tumbler housing 17; The interlock pin 90 is, of course, returned to its outermost position in the groove 93 upon reverse rotation of the slide control disk 45. As will be obvious from an inspection of Figure 11, both ends of the groove 97 are equally spaced from the axis of the disk 45 so that the dial 38 is free to rotate when the stud 96 is seated at either extremity of the groove 97.

To provide a finished appearance for the look when positioned in the file cabinet, a faceplate 98, recessed to permit peripheral segments of the dial 38 and slide control disk 45 to project therethrough, is secured to the external surface of the top framing strip 12 of the file cabinet 11. The face plate 98 is provided withan arcuately projecting lip 99 immediately underlying the lower edge of the dial 38 and projecting perpendicularly from the plane of the face plate 98, the periphery of the lip 99 extending in coincidence with the portion of the dial 38 projecting from the top framing strip 12. While only preferred embodiments of the invention have been particularly shown and described, it is apparent that various modifications may be made in the invention without departing from the spirit and scope thereof, and it is desired, therefore, that only such limitations shall be placed thereon as are imposed by the appended claims.

I claim:

1. A combination lock comprising a lock housing, a plurality of peripherally recessed tumblers freely journalled in axial alignment within said housing for rotation, a rotatable driving cam supported for rotation adjacent said tumblers, a lost-motion driving connection between said driving cam and tumblers, a fence lever pivotally supported within said housing having a portion bearing on the periphery of said driving cam and having a fence fixed thereon extending transversely across the peripheries of said plurality of tumblers, said driving cam having a peripheral gate therein for receiving a portion of said fence lever when aligned with the same to permit pivotal movement of said fence level and fence toward said tumblers, reciprocally shiftable shield means supported on said driving cam for movement radially of the driving earn from a position shielding said driving cam gate against entrance of said fence lever portion therein to maintain said fence lever in a position spacing said fence from said tumbler peripheries to a position exposing said gate to said lever portion, a reciprocative bolt resiliently biased to project the same away from said tumblers, means interconnecting said fence lever and said bolt to retract said boltto an unlocked position upon rotation of said driving cam with said fence seated in said tumbler recesses, a cylindrical dial supported for rotation on said housing in axial alignment with said tumblers, a spindle interconnecting said driving cam with said dial for coordinating rotation of the same, a disk of substantially the same circular cross section as said dial rotatably supported in axial alignment with said dial for rotation through a selected arc between spaced limit positions to shift said shield means on said driving cam to expose said driving cam gate at one of said limit positions and to shield said gate at the other of said limit positions, spaced fixed shoulder means positioned to accommodate a portion of said shield means therebetween when said shield means is disposed at the gate-exposing position thereof and forming obstacles in the rotary path of said portion restricting rotation of said driving cam to a minor arc, means for preventing shifting of said shield means from the gate-shielding position thereof when said driving cam occupies the range of angular positions lying outside of said minor arc, interlock means for selectively interlocking said dial with said lock housing to prevent rotation of said dial, and means positioning said interlock means in response to the position of said disk to interlock said dial with said housing when said disklies in the intermediate zone of said arc, said interlock means comprising a pin supported on said dial for radial movement toward said lock housing, said lock housing having a notch therein to receive said pin at one position only of said dial for interlocking said dial against rotation relative to said housing and said disk having a guide groove therein in which said pin is seated for positioning said pin radially of said dial.

21A combination lock comprising a lock housing, a plurality of peripherally recessed tumblers freely journalled in axial alignment within said housing for rotation, a rotatable driving cam supported for rotation adjacent said tumblers, a lost-motion driving connection between said driving cam and tumblers, a fence lever pivotally supported within said housing having a portion bearing on the periphery of said driving cam and having a fence fixed thereon extending transversely across the peripheries of said plurality of tumblers, said driving cam having a peripheral gate therein for receiving a portion of said fence lever when aligned with the same to permit pivotal movement of said fence lever and fence toward said tumblers, reciprocally shiftable shield means supported on said driving cam for movement radially of the driving cam from a position shielding said driving cam gate against entrance of said fence lever portion therein to maintain said fence lever in a position spacing said fence from said tumbler peripheries to a position exposing said gate to said lever portion, a reciprocative bolt resiliently biased to project the same away from said tumblers, means interconnecting said fence lever and said bolt to retract said bolt to an unlocked position upon rotation of said driving cam with said fence seated in said tumbler recesses, a'cylindrical dial supported for rotation on said housing in axial alignment with said tumblers, a spindle interconnecting said driving cam with said dial for coordinating rotation of the same, a disk of substantially the same circular cross section as said dial rotatably supported in axial alignment with said dial for rotation through a selected are between spaced limit positions to shift said shield means on said driving cam to expose said driving cam gate at one of said limit positions and to shield said gate at the other of said limit positions, spaced fixed shoulder means positioned to accommodate a portion of said shield means therebetween when said shield means is disposed at the gate-exposing position thereof and forming obstacles in the rotary path of said portion restricting rotation of said driving cam to a minor arc, means for preventing shifting of said shield means from the gate-shielding position thereof when said driving cam occupies the range of angular positions lying outside of said minor arc, interlock means for selectively interlocking said dial with said lock housing to prevent rotation of said dial, and means positioning said interlock means in response to the position of said disk to interlock said dial with said housing when said disk lies in the intermediate zone of said are, said interlock means comprising a pin supported in a radial groove in said dial accommodating said pin for limited radial movement toward said lock housing, said lock housing having a notch there in to receive said pin at one position only of said dial for interlocking said dial against rotation relative to said housing, and said disk having a guide groove therein in which said pin is seated, said guide groove having the ends thereof disposed at a greater distance from the axis of said disk than the remainder of said guide groove for inter locking said pin in said notch when the pin is disposed intermediate the ends of said guide groove.

3. A combination lock comprising a lock housing, a plurality of peripherally recessed tumblers freely jour nalled in axial alignment within said housing for rotation, a rotatable driving cam supported for rotation adjacent said tumblers, a lost-motion driving connection between said driving cam and tumblers, a fence lever pivotally supported within said housing having a portion bearing on the periphery of said driving cam and having a fence fixed thereon extending transversely across the peripheries of said plurality of tumblers, said driving cam having a peripheral gate therein for receiving a portion of said fence lever when aligned with the same to permit pivotal movement of said fence lever and fence toward said tumblers, a reciprocally shiftable shield supported on saiddriving cam for movement radially thereof having arcuate ends of the same radius as the periphery of said driving cam for shielding said driving cam gate against entrance of said fence lever portion therein to maintain said fence lever in a position spacing said fence from said tumbler peripheries, a reciprocative bolt resiliently biased to project the same away from said tumblers, means interconnecting said fence lever and said bolt to retract said bolt to an unlocked position upon rotation of said driving cam with said fence seated in said tumbler recesses, said housing having a projecting cylindrical tumbler housing portion, a cylindrical dial rotatably supported and axially aligned in nested relation about said cylindrical housing portion, a hollow sleeve interconnecting said dial and said driving cam for coordinating rotation of the same, a shaft rotatably supported in the hollow of said sleeve for rotation through a selected are between spaced limit positions having a cam on one end thereof for shifting said slide to expose said driving cam gate at one of said limit positions and shield the gate at the other of said limit positions, a disk complementary to the circular cross section of said dial overlying said dial in axial alignment therewith and fixed to said shaft, a pin supported on said dial for radial movement toward said cylindrical housing portion, said cylindrical housing portion having a notch in the lateral wall thereof for receiving said pin at one position only of said dial to interlock said dial against rotation relative to said housing portion, and said disk having a guide groove therein in which said pin is seated for shifting said pin toward said housing into interlocking relation in said notch when said shaft and disk lie in the intermediate zone of said are between said exposing and shielding positions spaced fixed shoulder means positioned to accommodate a portion of said shield means therebetween when said shield means is disposed at the gate-exposing position thereof and forming obstacles in the rotary path of said portion restricting rotation of said driving cam to a minor arc, and means for preventing shifting of said shield means from the gate-shielding position thereof when said driving cam occupies the range of angular positions lying outside of said minor are.

4. The combination lock recited in claim 3, wherein means are provided on said cylindrical housing portion for restricting radial movement of said pin toward said housing portion at all positions of said dial except said one position for restraining said disk from rotation relative to said dial to shift said slide from said shielding position.

5. A combination lock comprising a lock housing, selectively adjustable tumblers rotatable about a common axis each having a peripheral recess, a bolt, a spindle having fixed thereto a driving cam for adjusting said tumblers, a dial fixed to said spindle for adjusting said driving cam, said spindle, driving cam and dial being rotatable about said common axis, a pivoted fence lever for reciprocating said bolt, said fence lever having a laterally extending fence adapted to lie transversely across the peripheries of said tumblers and having a nose bearing upon the periphery of said driving cam, said driving cam having a peripheral gate adapted to receive said fence lever nose to permit said fence to enter said tumbler recesses when the latter are adjusted in registry with said fence for moving said bolt, shielding means supported on said driving cam for movement radially thereof to a position shielding said driving cam gate against entrance of said nose therein and another position exposing said driving cam gate to entrance of said'nose therein, a manually adjustable member rotatable about said common axis between two angular limit positions relative to said common axis and said dial at one slected position of said dial for shifting said shielding means from gate-shielding position to gate-exposing position, spaced stationary means positioned in the path of a portion of said shielding means when the latter is shifted to expose said gate to restrict rotation of said driving cam to a minor portion of one revolution, interlock means for selectively interlocking said dial with said lock housing to hold the same against relative rotation, means intercoupling said interlock means with said manually adjustable member for shifting said interlock means in response to rotation of said manually adjustable member into interlocking relation between said dial and said lock housing when said dial occupies one selected angular position and said manually adjustable member lies in the intermediate portion of its range of movement between two angular limit positions and for positioning said interlock means in a noninterlocking position when said manually adjustable member occupies either of said two angular limit positions, and means coacting with said manually adjustable member and said interlock means for restraining said manually adjustable member against rotation relative to said dial when said dial is out of registry with said one selected position.

6. A combination lock comprising a lock housing selectively adjustable tumblers rotatable about a common axis each having a peripheral recess, a bolt, a spindle having fixed thereto a driving cam for adjusting said tumblers, a dial fixed to said spindle for adjusting said driving cam, said spindle, driving cam and dial being rotatable about said common axis, a pivoted fence lever for reciprocating said bolt, said fence lever having a laterally extending fence adapted to lie transversely across the peripheries of said tumblers and having a nose bearing upon the periphery of said driving cam, said driving cam having a peripheral gate adapted to receive said fence lever nose to permit said fence to enter said tumbler recesses when the latter are adjusted in registry with said fence for moving said bolt, shielding means supported on said driving cam for movement radially thereof to a position shielding said driving cam gate against entrance of said nose therein and another position exposing said driving cam gate to entrance of said nose therein, a manually adjustable member rotatable about said common axis between two angular limit positions relative to said common axis and said dial at one selected position of said dial for shifting said shielding means from gate-shielding position to gate-exposing position, spaced stationary means positioned in the path of a portion of said shielding means when the latter is shifted to expose said gate to restrict rotation of said driving cam to a minor portion of one revolution, interlock means, movably supported on said dial, said lock housing having means for accommodating said interlock means when said dial occupies one selected angular position for interlocking said dial against rotation relative to said housing, means intercoupling said interlock means with said manually adjustable member for positioning said interlock means out of interlocking relation with said housing when said manually adjustable member occupies either of said two angular limit positions and for shifting said interlock means in response to rotation of said manually adjustable member into said accommodating means on said lock housing to interlock said dial with said lock housing when said manually adjustable member lies in the intermediate portion of its range of movement between said two angular limit positions, and means coacting with said interlock means for restraining said manually adjustable member against rotation relative to said driving cam when said driving cam is out of alignment with said one selected position.

7. A combination lock comprising a lock housing, a plurality of peripherally recessed tumblers freely journalled in axial alignment within said housing for rotation, a rotatable driving cam supported for rotation adjacent said tumblers, a lost-motion driving connection between said driving cam and tumblers, a fence lever pivotally supported within said housing having a portion bearing aseaprs on the periphery of said driving cam and having a fence fixed thereon extending transversely across the peripheries of said plurality of tumblers, said driving cam having a peripheral gate therein for receiving a portion of said fence lever when aligned with the same to permit pivotal movement of said fence lever and fence toward said tumblers, reciprocally shiftable shield means supported on said driving cam for shielding said driving cam gate against entrance of said fence lever portion therein to maintain said fence lever in a position spacing said fence from said tumbler peripheries, a reciprocative bolt resiliently biased to project the same away from said tumblers, means interconnecting said fence lever and said bolt to retract said bolt to an unlocked position upon rotation of said driving cam with said fence seated in said tumbler recesses, a dial supported for rotation on said housing in axial alignment with said tumblers, a spindle interconnecting said driving cam with said dial for coordinating rotation of the same, a shield adjusting member rotatable in coaxial relation to said dial through a selected are for shifting said shield means on said driving cam to alternately expose and shield the peripheral gate of said driving cam, said shield adjusting member being shiftable from a first position at one extreme of said are disposing said shield means in gateshielding relation to a second position at the other extreme of said are disposing said shield means in gate-exposing relation, spaced fixed shoulder means positioned to accommodate a portion of said shield means therebetween when said shield means is shifted to expose said gate and forming obstacles in the path of said shield means portion restricting rotation of said driving cam to a minor portion of one revolution, means having surfaces positioned in the path of movement of said shield means from the gate-shielding position thereof and extending over the range of angular positions of said driving cam forming the circular complement of said minor portion of one revolution for preventing shifting of said shield means from said gate-shielding position, interlock means carried by said dial and shiftable into a coacting accommodating portion of said lock housing at one selected position of said dial for positively interlocking said dial and said lock housing against relative movement, means intercoupling said interlock means with said shield adjusting member for shifting said interlock means in response to rotation of said shield adjusting member to interlocking condition with said lock housing when said shield adjusting member occupies the intermediate zone of said are and for positioning said interlocking means in a noninterlocking position when said shield adjusting member occupies either extreme of said arc, and means coacting with said interlock means and said shield adjusting member for holding said shield adjusting member against rotation relative to said dial at all but said one selected position of said dial.

8. A combination lock comprising a lock housing, selectively adjustable tumblers rotatable about a common axis each having a peripheral recess, a bolt, a pivoted fence lever for reciprocating said bolt, a spindle having tixedthereto a driving cam for operatively engaging said fence lever at one angular position thereof for moving said bolt, said fence lever having a laterally extending fence lying transversely across the peripheries of said tumblers and adapted to enter the recesses in said tumblers when the latter are in registry therewith, manually adjustable means displaceable relative to said driving cam to a position preventing said operative engagement of said fence lever with said driving cam, said lock housing having a projecting cylindrical tumbler housing portion concentric with said common axis, a cylindrical dial rotatably supported about said cylindrical housing portion in coaxial relation therewith and fixed to said spindle, a manual adjusting member disposed adjacent said dial and rotatable about said common axis through a selected are between spaced limit positions for adjusting said manually adjustable means to said position thereof upon movement of said manual adjusting means from one to the other of said limit positions, interlock means for selectively restraining relative rotation between said dial and said cylindrical housing portion including an interlock member movably supported on said dial adjacent the cylindrical wall of said cylindrical housing portion, accommodating means in said cylindrical wall of said cylindrical housing portion for receiving said interlock member at one angular position of said dial to lock said dial and housing against relative rotation, and said manual adjusting member including control means coacting with said interlock member to shift the same into said accommodating means therefor when said manual adjusting member lies in the intermediate zone of said arc and to withdraw said interlock member from interlocking relation with said accommodating means when said manual adjusting member lies at either of the extremes of said arc, and means coacting with said interlock member and said manual adjusting member for restraining the latter against rotation relative to said dial when said dial is in nonregistry with said one selected position thereof.

References Cited in the file of this patent UNITED STATES PATENTS 108,964 Brown Nov. 8, 1870 144,670 Gross Nov. 18, 1873 2,575,674 Miller Nov. 20, 1951 2,653,070 McClellan Sept. 22, 1953 2,687,636 Miller Aug. 31, 1954 2,722,820 Coffey Nov. 8, 1955 2,767,572 Miller Oct. 23, 1956 FOREIGN PATENTS 697,362 Great Britain Sept. 23, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION May 5, 1959 Patent No. 2,884,778

John G. Shmorhun printed specification that error atpears in thethat the said Letters It is herebjr certified requiring correction and x of the above numbered patent Patent should read as corrected below.

column 6,

Column 5, line 28, strike out "180 degrees"; line 75, strike out "for"; column 7, line 1, strike out -"approxi' mately 180 degrees"; column 9, line 40, for "level" read lever Signed and sealed this 22nd day of November 1960.

(SEAL) Attest: v

ROBERT C. WATSON KARL H. AXLINE Attesting Oificer Commissioner of Patents 

